<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>类选择器</title>
    <style>
        /* 类选择器：样式点定义，结构类调用 */
        .red {
            color: red;
        }
    </style>
</head>
<body>
    <ul>
        <li class="red">冰雨</li>
        <li>藏海花</li>
        <li>来生缘</li>
        <li>筑基</li>
        <li>练气</li>
        <li>元婴</li>
        <div class="red">变红色吧</div>
    </ul>
</body>
</html>